Design and Development of a Ka-band Interferometer for Cryospheric Applications

• Main Author: Vedantham, Harish K
• Format: Others
• Published: ScholarWorks@UMass Amherst 2009
• Subjects: Interferometry; Millimeter wave; Radar; Cryospheric mapping; Electrical engineering; Electrical and Electronics; Electromagnetics and Photonics
• Online Access: https://scholarworks.umass.edu/theses/220; https://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1322&context=theses

Topographic maps of the earth are essential to geographic and earth science studies. In particular, mapping and estimating physical parameters of the earth’s water and ice cover are critical to global climate studies. Among these, snow, ocean and fresh water topography, snow wetness and water equivalent are of immediate interest to the scientific community. Challenges in the instrument development and deployment posed by these required measurements are twofold. Firstly, these measurements are required to have global coverage, yet maintain stringent spatial resolution and accuracy margins. Secondly, snow topography measurement requires minimal electromagnetic wave penetration through snow, hence requiring the use of millimeter-wave frequency radars. While having the advantage of smaller and lighter structures, instruments at millimeter-wave frequencies are difficult to design, evaluate and deploy due to their mechanical and electric precision requirements. This thesis presents the design, development, detailed evaluation and first deployment of a Ka-band interferometer. An overview of the theory of interferometric mapping is presented including a discussion on instrument sensitivity and accuracy. Based in this theory, a geometric and hardware configuration for a rooftop deployment is arrived at. Detailed design and evaluation of the radar receiver is documented. Lastly first results from a rooftop and ground-based deployment are presented.